NVIS -
Night Vision Imaging
System
improves a pilot's ability
to see during periods of
darkness.
The following is explanation
about NVIS and NVG (Night Vision
Goggles) .
In
order to increase flight safety,
NVIS & NVG are used as aiding methods
during night flight operations
in both rural and urban areas.
Often time aerial law
enforcement operate with NVGs
which provide them with a wide
range of vision through the
goggles. Piloting with Night
Vision Goggles must be
accompanied by compatible
cockpit and external lighting
modification.
Modification of cockpits
include installing illuminated
cockpit instruments and displays
which are compatible with the
NVG. Infrared associated with
the illumination must be
eliminated so these secondary
lighting alternatives can be
effective in the cockpit and the
NVG can then pick up infrared
outside the cockpit to allow
visibility at night.
NVGs are electro-optical
devices that amplify existing
light, such as the stars, moon,
or sky, instead of a light
source of their own. Ambient
light is captured and
intensified by electronic means
to allow visibility through
night vision goggles. Light
entering through a lens produces
a green image of the outside
environment onto a screen which
is magnified when viewing with
night vision goggles.
The maximum viewing range of
NVGs are 100 feet to 400 feet.
Some objects viewed through NVGs
appear to be farther away
because we associate the loss of
detail sharpness with distance.
For this reason, NVG users tend
to overestimate distance and
underestimate the height of
objects.
